With Moorish Jav Cav, I've noticed that when I do need to charge I'm best off if I double click (or select a set up location and run to it) and then single click while my cav is still running. I've seen 40 of my base jav throwers charge a full unit of mailed knights and win with only about 10 losses doing this. This is with no experience for my cav.

The entire charge system seems to have some oddities to it. I wish there was a "Run here, form up and charge" command, as has been posted. It would be much more historic (from the commanders perspective) as most cav troops practice that manuver.